An OBTN is an optical transmission technology with a granularity between Optical Circuit Switching (OCS) and Optical Packet Switching (OPS), and its key idea is to make full use of a tremendous bandwidth of an optical fibre and flexibility of electronic control to separate a control channel from a data channel. A full optical switching technology is performed on a data channel by adopting Optical Burst (OB) switching unit-based data frames, and control frames and data frames in a control channel correspond one to one and control frams are also transmitted in the optical domain, but are switched to the electric domain for processing at nodes to implement reception and update of corresponding control information in a continuous reception and transmission manner. It will be understood that there may be more than one data channel and more than one control channel, and a section of Fibre Delay Line (FDL) with a fixed length may be utilized to delay bursts in each data channel in case of output competition of the bursts of multiple data channels; and when data frame and control frame channels simultaneously reach a certain node, or the node has no sufficient time to perform reception and transmission control of data frame according to an indication of a control frame after receiving the control frame, the FDL may be utilized to delay the data channels, delay time being exactly equal to time for processing control frame at each node, so as to compensate for a delay difference between the control channels and the data channels to solve the problem of competition. Therefore, an OBTN may implement dynamic adaptation to and good support for various traffic scenarios, and may improve resource utilization efficiency and network flexibility; and in addition, the advantages of high speed, high capacity and low cost of an optical layer are reserved, and applicability to various topologies such as star/tree/ring network is achieved.
However, using an FDL in a current OBTN technology may make a loop length reach a certain fixed length and has requirements on use of a delay optical fibre for realizing a specific relationship between a data frame and a control frame in a node, setting of an OB packet into a fixed length and setting of a guard interval into a fixed length, thereby complicating a network design, bringing high cost, making length control complex, inadequately keeping a network stable and making it difficult to construct and regulate the network when the loop length changes.